present only at and above vertebra T6 --> distinguishes ascending fibers within the gracile fasciculus (lower extremity) from cuneate fasciculus (upper extremity)
L1 in adult L3 in newborns
dorsal and ventral nerve roots of spinal nerves L1 through coccygeal 1
extension of pia mater that reaches from the conus medullaris to the end of the dursal sac at the vertebral level S2
what is contained with epidural space?
fat and internal vertebral venous plexuses
lateral extensions of pia mater that attach to dura mater, thereby suspending the spinal cord w/in the dural sac
which artery supplies the ventral 2/3 of the spinal cord?
anterior spinal artery (arises from vertebral arteries)
which artery(s) supplies the dorsal 1/3 of the spinal cord?
posterior spinal arteries (2 of them) that arise from vertebral arteries or the PICA
significance of great radicular artery (artery of Adamkiewicz)
this artery makes a major contribution to the anterior spinal artery and provides the main blood supply to lower part of spinal cord
anterior spinal artery syndrome -- cause?
ligation of great radicular artery during resection of an abdominal aortic aneurysm
anterior spinal artery syndrome - symptoms
paraplegia - bilateral spastic paresis w/ pyramidal signs below lesion impotence loss of voluntary control of bladder and bowel bilateral loss of pain and temperature sensation bilateral Horner syndrome bilateral flaccid paralysis